Apparatus for making soap and the like



Nov. 7, 193. B. CLAYTON APPARATUS FOR MAKING SOAP AND THE LIKE OriginalFiled May 28, 1937 //v VENTOR m Y H .A L m Nm M H A c Wm Z W VH 6ATTORNiYS.

Patented Nov. 7, 1939 PATENT OFFICE AIY'PARATUS For. MAKING soar AND THEW LIKE Benjamin Clayton, Houston, Tex., assignor to Refining, Inc.,Reno, Nev., a corporation of Nevada Original application May 28, 1937,Serial No. 145,246. Divided and this application February 23, 1938,Serial No. 191,878

9 Claims. (Cl. 8716) My invention relates to a novel apparatus forreacting materials and separating vapor from.

the reaction products. While applicable to the requirements of variousprocesses, it will herein be exemplified with reference to themanufacture of soap and the removal of glycerine therefrom, the novelapparatus of the present invention being well adapted to the process.

It is known that a material selected from the group including fats,oils, greases, fatty acids,

' and like substances, herein-termed a saponifiable material, can besaponified by an agent,

such as caustic soda, caustic potash or similar' saponifying substances,usually alkaline, herein termed a fsaponifying material, by batch orcontinuous operations to form soap. The continuous method involvessaponification of a suitable mixture during flow through aheaterpreferably of the type providing a coil in which heat is appliedduring stream flow. It has been proposed to heat progressively thestream flowing in such a coil until a temperature is reached which issufficiently high to vaporize glycerine and water, and to separate theglycerine under vacuum conditions.

It has been found that, if any material portion of the saponifiablematerial remains in unsaponifled condition when temperatures of aglycerine-freeing value are applied, a reversion or a discoloration islikely to occur. The resulting discoloration is not detrimental inmaking certain soaps, but is a drawback in continuously producing thewhitest soaps when it is desired to remove substantially all of theglycerine therefrom. Tests indicate that the presence of a very smallquantity, even a fraction of one per cent, of such unsaponifiedsaponifiable material may cause discoloration in making certain soaps ifglycerine-freeing temperatures are applied while such traces arepresent.

When the entire operation takes place in one reaction zone, the productssometimes reach the higher discolorating temperatures before all of thesaponifiables have been saponified. For'example, if saponifying andglycerine-removing temperatures are applied in the same coil or passage,it is sometimes difficult to prevent such discoloration when reactingcertain saponifiable and saponifying materials. If the lower section ofsuch a coil is kept hot enough to effect separation of the glycerinewhen the soap is subjected to low-pressure conditions, the uppersection, in which saponificationtakes place, cannot usually be keptbelow the temperature at which the traces of unsaponified saponifiablematerial will cause discoloration. The increase in temperature may bequite rapid in the saponifying section of such a coil and discoloringtemperatures may be reached while traces of unsaponifled saponifiablematerial are still present, even though the saponifying reaction mayprogress rapidly.

The discoloration when such traces are present can probably beattributed to a splitting or cracking of such traces of unsaponifiedsaponifiable material when the requisite glycerine-removing temperaturesare applied. The result is the formation of fatty acids, a portion ofwhich may decompose and produce discoloration of the resulting soap.However, regardless of the reactions which actually take place, I havefound that the tendency toward discoloration, which may be otherwisepresent in saponifying certain materials, can be overcome by theexpedient of largely eliminating the presence of such unsaponifiedsaponifiable material before subjection to the more elevatedtemperatures needed for glycerine removal.

Elimination of such traces can be effected by various expedients, thesimplest of which involves a mixing action. When saponifying andglycerine-removing temperatures are applied in the same coil or passage,the mixing action therein is limited by the mild turbulence resultingfrom stream flow through such a passage. This in turn depends uponfactors of velocity, size of the passage, etc., and also upon theviscosity of the material in the stream. In a soapmaking process, thisviscosity may be such as to preclude the possibility of the moreintimate mixing action herein-contemplated to eliminate by conversionthe traces of unsaponified saponifiable material. It'is an object of thepresent invention to apply a more pronounced mixing action than ispractical due to flow through an elongated reaction zone.

In the present invention, it has been found desirable to saponify in onezone and apply glycerine-removing temperatures in another, regardless of.whether or not a mixing action is utilized therebetween, thus making itpossible to apply only suflicient heat to the first, or reaction zone,to effect the desired saponification- These zones can be of the same ordifferent size,

and saponification can be effected under condi-.

two zones may be formed-by two coils with a mixing means therebetween?Such an intermediate means can perform merely the mixing function, or itcan be used in additional capacities in the system. For example, themixing action may be performed by a suitable pump which can, in turn,maintain controlled conditions in each zone-conditions best adaptedrespectively for saponification and removal of glycerine. If the mixtureof saponifiable and sapom'iying materials flows into a single coil, thepressure in the first, or saponifying section, thereof must necessarilybe higher than in the second section. This requires saponification athigher pressure than in the zone where the higher glycerine-removlngtempe atures are used.

It is an object of the present invention to provide a novel apparatusfor removing traces of unreacted material in the reaction productsissuing from a reaction zone. In the manufacture of soap, it is anobject of the present invention to eliminate such traces of unsaponifiedsaponiflable material as might cause objectionable dis coloration iftemperatures desired for glycerlne removal are applied while they arepresent.

Another object of the invention is to provide a mixing means whichreceives the reaction products from a reaction zone.

Another object of the invention is to use a pump which may serve in thismixing capacity and/ or which can be utilized in the maintenance ofcontrolled conditions in the reaction zone and in a subsequent zone.

Still another object of the invention is to utilize such expedients incombination with a vaporseparating means capable of separating vaporsfrom the unvaporized portion of the reaction products. If desired, theapparatus can be adapted to continuous processes in which streams of thematerials to be reacted are continuously mixed and sent to the reactionzone, after which they are subjected to the action of a mixing means orother means for insuring delivery to the subsequent equipment ofreaction products which are completely reacted.

Still another object of the invention is to provide a novel apparatus inwhich the reaction can be performed at a pressure which, if desired, maybe different from the pressure in a subsequent heating zone wheretemperatures facilitating separation of vapors are employed.

Another object of the invention is to provide an apparatus which can beused to increase the pressure between the point of discharge from thereaction zone and the point of entrance into a subsequent heating zonewhile at the same time exerting a mixing action on the reactionproducts.

In some instances, I have found it desirable to use a pump on both endsof a reaction zone to better control the pressure and flow conditions bytheir mutual action, and it is an object of the herein-describedinvention to provide such an apparatus. 7

It is a further object of the present invention to provide a novelapparatus in which the reacting materials can be first mixed and thenintroduced into a pump to effect further mixing and 'to increase thepressure thereon, after which the resulting mixture moves into areaction zone. If the reaction zone comprises a passage, such as 'isformed by a pipe or coil, such a system has the advantage that the pumpcan overcome, at least partially, the pressure head developed by howthrough the passage and at the same time reduce the pressure in themixing zone. Another object of the invention is to use tw proportioningpumps for respectively pumping the two materials into a mixing zone andto apply a pumping action in or beyond this zone to reduce the pressurerequired of the proportioning pumps. This permits a more satisfactoryoperation of many types of proportioning pumps and increases theirmetering accuracy. There is less chance of leakage or non-proportionaldelivery because of the fact' that the proportioning pumps operateagainst this reduced pressure.

It is another object of the present invention to provide an apparatus bywhich one or both of the materials to be reacted may be preheated beforemixing. In the manufacture of soap, such preheating involves applicationof temperatures higher than those previously contemplated for merelybringing the saponifiable material into condition for pumping, for thedesirable preheating temperatures are considerably above thoseheretofore suggested to melt the fat, for instance.

Further objects and advantages of the invention will be made evidenthereinafter.

One embodiment of the present invention particularly applicable to themanufacture of soap is illustrated in the accompanying drawing, thoughit will be clear that the invention is not limited to the particularapparatus or elements herein shown. In the drawing:

Figure 1 diagrammatically illustrates a complete soap-making system.

- Figure 2 is a vertical sectional view of the preferred type of mixerbetween the saponification zone and the subsequent heating zone.

Figure 3 is a vertical sectional view of the control means for theburners of Figure 1.

Referring to Figure 1, tanks 5 and 6 may respectively contain thesaponifiable and saponifying materials heated, if necessary, to suchtemperature that they can be readily pumped therefrom. Proportionedquantities of these materials are respectively withdrawn by continuouslyoperating proportioning pumps I and 8, driven by a motor or other drivemeans 9. Any suitable means is used for relatively varying the pumpingaction of these pumps, for instance, a variablespeed connection H!therebetween. If desired, preheaters H and 12 may be disposed betweenthe tanks 5 and 6 and their respective pumps 1 and 8 to apply thedesired preheating temperatures to either or both of the materials.Coiltype heaters are shown but these can sometimes be dispensed with inthe event the higher preheating temperatures are not to be employed. Inother instances, the preheating temperatures may be applied in the tanks5 and 6.

The pumps 7 and 8 respectively discharge streams of the saponifiable andsaponifying materials into a mixing zone of a mixer 18. Any suitablemixing means can be used but it has been found eminently successful tointroduce one of these materials into a flowing stream of the other toform the preliminary mixture. In many instances, no additional mixingaction need be used, the mixture moving directly to the saponifyingzone. However, in the preferred embodiment, this mixture flows through apipe [9 to a pump 20 which may likewise be operatively connected to thedrive means 9 through a shaft 2| and variable-speed connection 22. Thispump will build up the pressure requisite to send the mixture into thesaponifying zone and, at the same time, it can be used to reduce thepressure in the mixer l8 so that the proportioning pumps 1 and 8 can actagainst a lower pressure than would otherwise be the case, with theattendant advantages previously mentioned. In addition, the pump may beof a type adapted to additionally mix the materials in the event that itcoil 24 disposed in'a shell 25 and being'heated by a burner 28 which iscontrolled by a control traces of unsaponifled saponiiiable material,preferably by a conversion thereof, to produce a completely saponifiedproduct within the meaning of this term hereinafter set out. Variousexpedients can be used in this capacity but I have found it verysatisfactory' from a commercial angle to move the soap mixture into amixing 'zone and there apply such mixing action as will insure reactionof these traces to convert same into soap. When thus mixed, theremaining traces of unsaponifled saponiilable material will be quicklysaponified, thisaction being completed either in the mixing zone or in apipe 29 into which the product moves. If all discoloration is to beprevented, such traces of unsaponified saponiflabie material should beremoved before application of glycerine-removing temperatures.

A pump may be used to perform this mixing step and, if desired, mayperform the additional step of'increasing the pressure on the soapmixture, thus making it possible to operate at pressures lower in thesaponiflcation zone than in the subsequent zone where glycerine-removingtemperatures are applied. Such a pump is indicated in Figure 1 by thenumeral 38. Various types of pumps can be used in this connection,

whether of the rotary or reciprocating type. The

mixing action taking place in both types of pumps I is shown, themixture in a reciprocating pump taking place mainly in the valves. Thedevice which I prefer to use in performing this mixing action and, ifdesired, a pumpinh action is a screw conveyor, best shown in Figure 2. Avery satisfactory mixing action results by the use thereof and such adevice can also be used to somewhat increase the pressure, or it may beso operated that itsprimary function will be to effect the desiredconversion of the traces of unsaponiiied sapon- .flable material withoutgreatly increasing the pressure on the soap mixture during passagetherethrough.

Referring particularly to Figure 2, this screw conveyor provides ahousing it in which a screw shown, thisis effected by sets of beveledgears 34 v and 35 with a variable-speed means it 50 conto better themixing action. However, in some instances, this perforated plate can bedispensed with. Such a screw conveyor falls within the definition of theterm pump, as this term is herein-used. It may be provided with a jacket38, through which a material may be circulated in heat-transferringrelationship with the-material flowing therein. Sufficient heat may beem- .ployed at this point to maintain or increase th temperature.

On the other hand, it should be clear that the desirable mixing actioncan be obtained by means other than a pump. For example, the mixingaction can be performed by setting up in the soap mixture a turbulencegreater than that normally present in the coil 24. The control means 21may be used in this capacity, either to the exclusion of the pump 30 orto supplement the mixing action of such a pump. In other instances, aseparate turbulence-producing means can be used. In Figure 3, there isshown a control means which serves the dual purpose of controlling theheat applied to the reaction zone and effecting mixing throughturbulence incidental to a reversal of direction of flow therethrough.

Referring particularly to Fig. 3, the coil 24 discharges into a passageof a head 4| and the soap mixture flows rightward in an inner tube 42providing an open end 43 which is split and flared so as to becentralized with respect to an.

outer tube 44. The right-hand end of the tube 4.4 is closed by a movablehead 45 so that the soap mixture must reverse its flow and move leftwardthrough the annular space between the inner and outer tubes 42 and 44,being discharged through a passage 46 of the head 4| into the pipe 28.

The head 45 moves horizontally in response to the expansion andcontraction .of the outer tube 44.. 48 which cooperates with a seat 49in controlling the amount of fuelmoving through a pipe 50 to the burner26. Such a control means is capable of delivering to the pump 30, or tothe subsequent Attached to this head is a valve member heater, a soapmixture of constant character and in which any desired portion of thewater may be in the form of steam. On the other hand, if

the presence of steam is not desired, such a control means will act inthe nature of a thermostat to control the heat applied to the reactionzone.

A device of this character can be designed ,to rather intimately mix thematerials flowing therethrough, most of the mixing action taking placedue to turbulence at the right-hand end of the inner tube 42 where thedirection of flow is suddenly reversed;

To provide for adjustment of the control means. i

are moved horizontally as a unit. Such movement can be'used to adjustthe' space between the valve member 48 and the seat 49.

Referring again to Figure 1, the pressure before and after movingthrough the pump 30 may a 'be read from gauges 63 and 64 respectively inthe pipes 28 and 29. A thermometer 65 can be used to indicate thetemperature. n

The pipe 29 continuously delivers the completely saponifled mixture to aheater 8! wherein it is raised to a higher temperature. The pre- 'ferredtype of heater applies heat to the mixture "during stream flow throughan elongated passage 16 defined by a pipe or coil 00. External heatingof the coil 09 can be obtained by any suitable means, such as from theproducts of combustion from a burner I supplied with fuel through a pipeII. A valve structure 12 may be used to control the amount of fuel,being regulated by a suitable control means, indicated in general by thenumeral I3, and which is preferably of the type shown in Figure 3.

The heated products then flow continuously through a pipe I equippedwith a pressure gauge 16 and a thermometer I1, and are discharged in avapor-separating chamber 80, which is preferably maintained undervacuum. If desired, a nozzle 8|, providing a restricted orifice, can beused for thus discharging the products, in which event such a nozzlewill act to build up a low back pressure in the coil 00 and can be madeto liberate additional glycerine vapors by flashing when the productsmove therethrough. Usually, however, it is better not to throttle theflow too much at this point but to operate at sufllciently hightemperature that much of the glycerine is in vapor form in the pipe 15.In many instances,

no restriction of the passage at the point of discharge need be used.

If substantially all of the glycerine is to be removed, I have found itdesirable to collect the soap in the vapor-separating chamber 80 inmolten, plastic, or semi-plastic condition. To facilitate this end, acontainer 02, which defines the vapor-separating chamber 00, can besurrounded by a jacket 83 through which a suitable heating medium can becirculated, or steam or other hot gaseous medium may be introduceddirectly into the vapor-separating chamber 00 to apply heat thereto andalso to facilitate glycerine separation under the law of partialpressures. Heat thus applied is also of value in facilitating glycerineseparation in the chamber 80 and preventing condensation therein.Separation of glycerine vapor is further facilitated by so directing theincoming products that they impinge against and flow downward along theinner wall of the container 82, for instance in a path indicated by thedottedline 85.

'If water has not previously been separated from the saponified mixtureor product, this water can be withdrawn in vapor state along with theglycerine vapors. In the system shown, such vapors are continuouslywithdrawn through a pipe 81, equipped with a pressure gauge 08 and athermometer 89, at such rate as to maintain an effective vacuum in thechamber 80. As shown, these vapors move through tubes 00 of a glycerinecondenser 9|, a suitable cooling medium being circulated exterior ofthese tubes so as to condense the glycerine which then moves downward ina receiver, such as a barometric column 92 of sufficient height tocounteract the vacuum and which discharges the glycerine in submergedposi tion in a tank 94. Any uncondensed vapors are withdrawn through apipe 05 and flow to a water condenser 96 which may be of the jet typesupplied with cooling water through a pipe 91. The condensate and thecooling water move downward through a similar barometric column 00 withits lower end submerged in water in a tank 99. continuously withdrawn bya vacuum pump I00 which is utilized in maintaining the vacuum conditions in the vapor-separating chamber 00.

The soap reaches the lower end of the vaporseparating chamber 00 inmolten, plastic, or semiplastic condition in the preferred mode oi.opera- Any uncondensed vapors or fixed gases are tion and is preferablywithdrawn continuously by any suitable means which will not impair theeil'ective vacuum therein. In the embodiment illustrated, it movesthrough a suitable slot in the lower wall of this chamber into aconveyor housing I02. Delivery of the soap to this housing may beexpedited by use of a suitable agitator or scraper revolving in thechamber 80, not shown. Positioned in the housing I02 is a screw I03driven by any suitable means, such as a gear I04 operatively connectedto a drive means not shown. Only a small clearance exists between thescrew and the housing I02 so that the soap is continuously forced to theright along this housing and into an intersecting housing I05 providedwith a screw I00 driven through a gear I01. The soap may be dischargedinto the atmosphere, or into subsequent processing equipment by being extruded through an orifice I00.

It is very desirable to cool the soap, if withdrawn in molten, plastic,or semi-plastic condition, before exposure to the atmosphere. Thiscooling-is preferably accomplished during flow through the conveyors andI have diagrammatically shown jackets I09 and H0 around the housings I02 and I 05 to cool this soap. Other cooling means can be utilized, ifdesired. A suitable amount of moisture, builders, fillers, perfumes, andthe like can be added to the soap by being introduced into the conveyorhousing I05 or such materials may be subsequently added, if desired.

In operating this system to produce a neutral soap, it is desirable touse sufiicient saponifying material to react completely with thesaponiflable material. A slight excess can be used in the event it isdesired to produce a slightly alkaline soap.

It should be clear that the invention contemplates saponifyingtemperatures and glycerineremoving temperatures which can be applied indifferent zones to obtain the advantages mentioned above. It is onlynecessary to supply sufficient heat to the saponifylng zone formed bythe coil 24 to efiect saponification. The desirable temperatures andpressures in this zone will vary with different saponiflable materialsand no exact ranges can be set forth. Temperatures best suited to thesaponiilcation step can readily be ascertained empirically. Usually,however, it can be said that temperatures above a range of about 425-450F. should be avoided in the saponifying zone, though with certainsaponifiable materials, it is possible to go above this range with outdetrimentally aiIecting the process. Usually, temperatures below thisrange are quite satisfactory and are preferred. In producing soap fromsuch materials as tallow, vegetable oils and fats, etc., temperaturesbetween 350 and 425 F., or even lower, are quite satisfactory in thedischarge end of the reaction zone. The pressure in this zone can bevaried over wide limits but it is desirable to maintain suflicientpressure to assist in the fat-splitting reaction. Pressures as indicatedby the gauge 03 may range from 50 lbs/sq. in. to 250 lbs/sq. in. in mostinstances, though the system can be operated at pressures without thisrange. The pressure at the discharge end of the pump 20 will be abovethat present at the discharge end of the reaction.or saponiilcation zoneby an amount substantially equal to the friction head developed by flowthrough this zone.

Temperature and vpressure conditions in th saponifying zone can becorrelated to vaporize none or a material proportion of the water.

With the screw-type-mixing means shown in Figure 2, the soap mixture canbe satisfactorily handled even though a large percentage of the' waterhas been vaporized, if this mode of operation is desired, and there willbe no clogging, binding, or vapor lock. 2-: Other types of pumpsoperating to substantially increase the pressure will sometimes requirelimitation of the amount of steam present in the intake of such a pump.The invention is capable of a mode of operation in which no steam isformed in the saponiflcation zone or in which a material portion or allof the water has thus been converted into vapor state.

Heat applied to the saponiiication zone formed by the coil 24 may besupplemented by preheating of the soap-making materials, and manyadvantages accrue from preheating the saponiiiable material and, in someinstances, the saponifying material. The desirable preheatingtemperatures are above those necessary to put the usual fat in suchcondition that it can readily be pumped. Temperatures in theneighborhood of IOU-120 F. usually suflice in that connection but thepreheating temperatures herein-preferred are much higher. They willdepend in large measure upon the particular saponiflable materialutilized. With some saponifiable materials, temperatures up to orsomewhat above, 400 F. have been used with success with acorrespondingly decreased temperature rise in the saponification zonedefined by the coil 24. Usually, however, the desirable preheatingtemperatures will be below this value, and a commercial range of fromabout 200350 F. will be found best. Preheating of thesaponlfying'matcrial can also be used with success though this isnotessential.

By preheating caustic, for instance, to about 100-220 F., verysatisfactory action is obtained. It will be clear that these ranges aremerely exemplary and can be departed from, and that such preheating ofthe 'saponifiable or saponifying materials is not always essential.However, preheating does distinctly improve the continuoussaponification step and also reduces materially the pressure necessaryto force the stream through the coil 24. This is probably due to thefact that. when the preheated saponifiable material is brought intocontact with the saponifying material, a thinner and free-flowing streamresults. Under preheating conditions, the soap which starts to formalmost instantly is more in the form of a sol or jel, as distinctfrom aform which tends to clog or clot in the coil 24 and which results in theabsence "of preheating o! the saponiflable material. -Further, thereaction time is less with preheated materials and the continuoussaponiflcation step is more eflective and emcient. In addition, the pump20, if used, will usuallyoperate better and more effectively if a properdegree of preheating is used on either the saponifiable material or thesaponifying material, or on both.

Similarly, it is impossible to specify definite ranges of temperatureand pressure in the heater 68. It can be said, however, that, ifglycerine is to be removed, the temperature applied at-this" point isinvariably higher than that applied in the reaction zone. The formationof vapors in this elongated pass age defined by the coil 68 will; bedependent upon the heat applied and the pressure therein. Ifa nozzle IIis used, the entire length 01' this elongated passage may be atsuperatmospheric pressure. However, ii the nozzle is dispensed with, thepressure therein will be somewhat lower and, under such conditions, thevacuum will assist in moving the completely saponified material throughthis passage.

If glycerine is to be substantially completely removed, it is usuallynecessary to supply sumcient heat to the elongated passage to vaporizethe water, if still present, and usually to vaporize a portion of theglycerine. Tests indicate that glycerine'removal is facilitated bysupplying sufllcientlyhigh temperatures, either in the elongated passageor in the chamber 80, or both, so that the separated soap issubstantially anhydrous and exists in this chamber in molten, plastic,or semi-plastic condition. The soap need not be in such condition thatit is extremely liquid if the higher temperatures requisite to thiscondition are not desired. Substantially all of the glycerine canusually be removed from most soaps made by the process if the soap is ina plastic or semi-plastic condition, as distinct from a mass of solidsoap particles. With other soaps, the more liquid condition ispreferable if substantially all of the glycerine is to be removed.Experiments indicate that, while there is a rather definite meltingpoint for various soaps, once the soap has assumed this state, thetemperature can be reduced many degrees below the melting point withoutcausing the soap to become actual ly solidified. This factor gives arange of permissible temperatures in the -yapor separating chamber 80,the upper temperatures being considerably above the melting point of theparticular soap being produced, and the lower temperature in this rangebeing considerably below this melting temperature but above thetemperature at which the mass of soap actually solidifies and departsfrom its semi-plastic, plastic, or

strictly molten condition.

' If no heat is supplied to the vapor-separating chamber 80, it will befound desirable to 'use somewhat higher temperatures in the elongatedpassage formed by the coil 69 than would otherwise be the case. Inmaking soap from cottonseed oil', temperatures above 455 F. arepreferable ii. the soap is to be collected in molten, plastic, orsemi-plastic condition. With many other saponiflable materials,temperatures above 500 F. are desirable if no heat is supplied to thevapor-separating chamber 80. Temperatures from 540 to over 600 F. may beemployed. All of these temperatures can be somewhat lower if heat isalsosupplied to the vapor-separating chamber 88 but, in most instances,I prefer to use temperatures near those mentioned above, even ifadditional heat is thus supplied to the chamber-II in an amountsuflicient to maintain the soap in molten, plastic, or semi-plasticcondition without such cooling as would cause it to depart from suchcondition, or if an amount of heat is added suflicient to actuallyincrease the temperature of the soap therein. The degree of vacuum inthe chamber 80 is preferably high if substantially all of the glycerineis to be removed. A vacuum of 27-28 inches of mercury is quitesatisfactory. The absolute pressure therein can be considerably higherif all or a material portion of the glycerine is to remain in the soap.If a substantially glycerine-free soap is not desired, lowertemperaturescan be used in this elongated passage formed by the coil 69,andthe soap may collect and be withdrawn from the chamber II in powderedform. Even thenyapplication of heat to the chamber 80 will facilitateglycerine removal, though I have found that substantially all of theglycerine cannot heremoved commercially unless the soap is collected andwithdrawn from this chamber in molten, plastic, or semi-plasticcondition and unless a vacuum is maintained therein. The degree ofvacuum in the chamber 80 is preferably high if substantially all of theglycerine is to be removed from the soap.

Another factor in glycerine removal is the time during which the soap isin the chamber 80. If the soap is collected in molten, plastic, orsemiplastic condition, the time of exposure to the vacuum can beincreased by impinging the reaction products against the walls of thischamber, permitting the soap to flow down these walls with retardedvelocity. Soap under the temperature conditions existing in this chambermay discolor if left therein too long, but it should remain for a timesufficient to separate the desired amount of glycerine. Continuouswithdrawal after lapse of such a time is very advantageous.

As an example of the operation of the invention, I have produced a verywhite soap using a ratio of ten parts cocoanut oil to 7.5 parts of 31 B.sodium hydroxide. The reaction zone was defined by a coil ofapproximately inch internal diameter and was about 275 feet long. Themixture moved therethrough at a velocity of about one foot per second. Apump of the rotary or gear type was found satisfactory in effecting theintermediate mixing and the elongated passage was formed by a coil ofabout 275 feet in length, having an internal diameter of approximatelyinch.

In this example, the pressure at the intake end of the reaction zoneformed by the coil 24 was 200 lbs/sq. in. and at the intake of the pump30 was 125 lbs/sq. in. This pump increased the pressure slightly toabout 135 lbs/sq. in. and the pressure at the discharge end of theelongated passage formed by the coil 69 was about 60 lbs/sq. in. Norestricted-orifice nozzle was used in this example.

The temperature of the reaction products delivered from the reactionzone of the coil 24 was about 400 F. and this temperature was increasedin the coil 69 to about 525-550 F. A vacuum of 27 inches of mercury wasmaintained in the vapor separating chamber 80 and the soap wascontinuously withdrawn therefrom in plastic condition in such manner asnot to impair this vacuum. About 98% of the glycerine was removed.

It will be clear that various modifications can be made in the inventionwithout departing from the spirit thereof. For instance, the saponifyingstep can be performed by various means other than that shown and thedevice 30 will still serve its desirable function of converting anyunsaponifled saponifiable material before application ofglycerine-removing temperatures. Also, various devices can be used forheating the completely saponifled products to the desiredglycerineremoving temperatures though it is preferable that this heatingbe carried out during continuous flow. If the water is removed as avapor along with the glycerine, various expedients can be used forcondensing and separating these materials, the embodiment shown beingmerely illustrative. continuously withdrawing the soap without impairingthe effective vacuum. While it is possible to operate the system withsome degree of success if the soap is not continuously removed, it hasbeen found particularly desirable, especially when the soap is inmolten. plastic, or semi-plas- Finally, various means can be used fortic condition, to withdraw this soap from the chamber 8! continuously.

An important feature of the invention is the saponiflcation in a zoneseparate from that zone in which glycerine-vaporizing temperatures areapplied. The use of two heating zones through which the materials passin succession is of utility irrespective of the intermediate mixingstep, for the temperatures in the two zones can be controlled in amanner not possible where a single coil is used. In such a single coil,it is quite possible that the high temperatures will be applied to theupper or entrance section of the coil and cause discoloration of thesoap. Multi-stage heating corrects this and some easily saponificdmaterials can be practically completely converted before discharge fromthe first heater, particularly by proper design of this heater.

On the other hand, with most saponifiable materials, an intermediatemixing by turbulence, mechanical mixing or other expedients is desirablein order to eliminate the traces of unsaponifled saponifiable materialbefore application of glycerine-vaporizing temperatures.

Another feature of the invention is the preheating of one or both of thesoap-making materials with the attendant advantages mentioned above.This feature of the invention has utility regardless of the processingof the soap after moving through the saponification zone, and regardlessof whether the pump is used.

Another important feature of the invention is to use an auxiliary mixingmeans, which may well be the pump 20, between the zone where thesoap-making materials first come into contact and the saponiflcationzone, or even at the zone where these materials first contact. In someinstances, the proportioned streams may be delivered directly to such amixing means as is defined by the pump 20 whereby mixing and, ifdesired, increase in pressure are effected therein.

The above description with regard to the apparatus of the presentinvention used in the continuous manufacture of soap is illustrative ofits use in various other capacities wherein it is desired to reactmaterials, separate vapor from the reaction products and, if desired,process the non-vaporized material withdrawn from the vapor-separatingmeans.

Whenever in the specification or claims the words completely reacted orcompletely saponifled" are used, they are to be understood to meancomplete reaction or saponification within commercial tolerances.

Various changes can be made in the invention without departing from thespirit thereof as defined in the appended claims.

By the employment of the term mixing means or "mechanical mixing means,"I intend to define and embrace mixing devices which are interposed inthe line of flow of the materials and which are constructed and arrangedto intimately admix the unreacted materials after discharge from thesaponification devices and before introduction to the heating device, ascontradistinguished from the mere incidental mixing which occurs in thepassage of the mixture stream containing reactable materials; means forapplying heat to the stream moving through said reaction zone'to reactsaid materials; a container providing a vapor-separating chamber; amixing means; means for continuously conducting the reaction productsfrom the discharge and of said elongated reaction zone to said mixingmeans to form mixed products; means for conducting these mixed productsfrom said mixing means to said vapor-separating chamber; means forcontinuously withdrawing vapors from said chamber which separate fromthe non-vaporized material included in the mixed reaction productsentering said vapor-separating chamber; means for separately withdrawingsaid nonvaporized material from said chamber; and means for applyingheat to the reaction products at a position between said mixing meansand said means for withdrawing said non-vaporized material forfacilitating liberation of vapors from the non-vaporized material.

2. In combination in an apparatus for reacting materials and separatingvapors from the reaction products: a first heater providing an elongatedreaction zone; a second heater providing an elongated passage; means fordelivering a mixture of the materials to be reacted to said elongatedreaction zone; a mechanical mixing means for interconnecting saidelongated reaction zone and said elongated passage; a vaporseparatingmeans; means for conducting a stream of the reaction products from saidelongated passage of said second heater to said vapor-separating means;means for continuously removing vapor fromsaid vapor-separating means;-and means for separately and continuously removing non-vaporizedmaterial from said vapor-separating means.

3. A combination as defined in claim 2 in which said vapor-separatingmeans includes -a chamber and in which said vapor-removing meanswithdraws vapor .rom said chamber at such rate as to maintain a vacuumtherein.

4. A combination as defined in claim 2 in which said vapor-separatingmeans includes a chamber and in which said vapor-removing means with;draws vapor from said chamber at such rate as to maintain a vacuumtherein and in which said means for continuously removing non-vaporizedmaterial comprises a vacuum-sealing conveyor.

for continuously removing the non-vaporized material from saidchamber'without impairing said vacuum and discharging it into a zone inwhich the pressure is higher than in said chamber.

5. In combination in an apparatus for con- .tinuously making soap: afirst heater providing discharges; and a vacuum pump intaking' from saidvapor-separating chamber to maintain a vacuum therein.

6. In combination in an apparatus for making soap: a mixing meansincluding a pump; means for delivering proportioned quantities ofsaponifiable and saponifying materials to said mixing means, said pumpincreasing the pressure thereon and mixing said materials; a heatingmeans providing an elongated saponification zone with intake anddischarge ends; means connecting the intake end of said elongatedsaponiflcation zone to the discharge of said pump; a second pump; meansconnecting the intake of said second pump to said discharge end of saidsaponification zone whereby said pumps control the pressure in saidsaponification zone and said second pump mixes the reaction productsdischarged from said saponiflcatlon zone to destroy any traces ofunsaponifled saponifiable material.

7. A- combination as defined in claim 6 including'a continuous-glycerine-removing apparatus, and including means for connecting thedischarge end of said second pump to said glycerine-removing apparatusto utilize the discharge pressure of said second pump in moving thecompletely saponified reaction products into said glycerine-removingapparatus.

8. An apparatus for continuously making soap and recovering glycerine,comprising, incombination: a saponiflcation coil, means for pumpingpredetermined proportions of saponiflable'and saponifying materialsthrough said coil, heating means for imparting a relatively lowtemperature to the materials while they are undergoing saponification intheir passage through said coil, a separate and independent coil, meansfor connecting said coils together and a separate heating means adaptedto abruptly elevate the temperature of the previously saponlfied mixturepassing through said second coil, whereby to elevate the temperature ofthe soap suificiently to render it molten when anhydrous, a vaporseparating chamber, means for discharging the mixture from the secondheating coil to the vapor separating chamber whereby to separate themolten anhydrous soap from the glycerine,

means for recovering the glycerine and means for continuously removingthe molten anhydrous soap from said chamber.

9. A two-coil apparatus for making soap and recovering vapor impurities,comprising, in combination: a low temperature saponification coil, meansfor continuously advancing saponifiable materials through said coil, ahigh temperature coil separately disposed with respect to the lowtemperature coil, means for connecting said coils whereby the mixture iscontinuously advanced from the first coil to the separate coil, saidhigh temperature coil being adapted to drastically elevate thetemperature of the mixture of the previously saponified mixture to aglycerine freeing value, an exaporating chamber and means forintroducing the thus highly heated mixture to the evaporating chamber,means for withdrawing the vaporized glycerine from the evaporatingchamber and means for withdrawing the resultant soap in its highlyheated condition from said evaporating chamber.

BENJAMIN CLAYTON.

